Fluid feed device



Jan, 9, 1951 E, A WEAVER 2,537,497

FLUID FEED DEVICE Filed Dec. '7, 1946 "Patented Jan. 9, 1951 UNITEDSTATES Mmmg OFFICE FLUID FEED DEVICE Eastman A. Weaver, Winchester,Mass., assgnor, by mesnc assignments, to Stator Company, a corporationof Massachusetts Application December 7, 1946, Serial No. 714,799

6 Claims.

This invention relates to a self-regulating, continuous, heat-operated,fluid-feed device suitable for a wide variety of applications and, asillustrative of its utility, is herein shown as applied. to anejector-refrigeration,apparatus of the type illustrated in United StatesPatent 2,174,301, granted September 26, 1939.

The principal object of the invention is to replace many of the complex,expensive, shortlived feed pumps now used by a single relativelyinexpensive device subject to little wear and requiring no mechanicalpower supply. Other objects are to provide a hermeticallysealedautomatic boiler feed suitable for apparatus, such asrefrigeration systems, using a permanent selfcontained charge of fluidwhich must not leak away or be contaminated by atmospheric leakage; andto provide a boiler feed adapted to replace hand-controlled boilerfeeds, such as injectors, by a self-regulating apparatus which willfunction only when needed. Further objects will be apparent from aconsideration of the following description. n

It is known that boiling gas-free liquids pass into the vapor phase notcontinuously,y as in evaporation, but in a series of fbumps caused bythe fact that minute bubbles cannot form until substantial superheatingof the liquid above its boiling point has occurred, at which time asizable bubble appears, sometimes with such violence as to break a glasscontainer. lf the liquid be confined within an elongated chamber or tubein which a series of co-directed check valves are interspaced to definecompartments at least partially filled with the boiling liquid, thebumping or sudden formation of each bubble tends to expel part of thefluid from its compartment and, due to the action of the check valves,the expulsion of the uid is limited to one direction. By continuing thebumping action by applying the required degree of heat to thecompartment, the intermittent oscillating pressure thus produced can berectified to produce a flow of fluid even against a large pressuredifference, if the number of units is adequate. The principle thusinvolved is to be distinguished from the action of a percolator whichinvolves an air-lift principle working against little or no appreciablepressure head, and which does not depend uponintermitt'ent generation ofvapor from a superheated liquid.

The invention may advantageously be applied to absorption-refrigerationapparatus to feed an absorbent-refrigerant solution, or toejector-refrigeration apparatus to feed ak propellant fluidautmatically. Mathe beilerrgainsi a. Substanf..

. 2 -f tial pressure, thereby permitting operation with'- outmechanically-actuated valves or pumps which require power and usuallyinvolve more or less leakage to the atmosphere. This may be accomplishedby including as a part yof a boiler or generator a heated conduitcomprising a series of codirected check valves constructed and arrangedso as to dene a plurality of spaced compartments each containing theboiling uid. The conduit may communicate with the boiler proper or amanifold, except in certain cases where it may prove advantageous tomake the entire boiler of these' valve-spaced conduits arranged inseries and/or in parallel, as for example in absorption refrigeration,where separation of fluids by distillation is involved and maintaining apressure difference is essential. i

Since such a device is actuated by individual bubbles, it works lbestwith the boiler compartiments'quite small. Thus, its unique advantagesare most apparent for small apparatus, although it is to be understoodthat the conduits may be combined in parallel to furnish an adequatellowrequired for large installations, as well as in series to furnishrelatively high pressures.

In its simplified form, the device comprises a series of valve seatswhich are pressed, soldered,

k brazed, or otherwise secured at intervals within f developed withinthe compartments may be found` necessary, depending upon the particularcondi-P tions. The vertical arrangement for upward flow s has the"additional advantage of advancing Athe vapor preferentially as comparedwith the liquid, this being desirable, as the bumping is less ef"fective when cushioned by the presence of much vapor in the compartment,and hence the vapor should be passed out of the units or compart-' mentsas rapidly as possible. However, other considerations may lead to theplacing of these conduits horizontally or even for down flow inspecial'fcase's'.,

A Referring to the accompanying drawings which illustrate theapplication of my device to a typical absorption-refrigerationapparatus:

Fig. l is a diagrammatic view of the system embodying the presentinvention;

Fig. 2 is an enlarged vertical section through the boiler-feedingapparatus; and

Figs. 3 and 4 are sections on the lines 3-3 and 4 4, respectively', ofFig. 2.

The system herein shown comprises a nre box or heating chamber Cequipped with suitable heating means, such as a gas burner B, and with-`in the chamber is a small boiler or vaporizor i which normally containsa body of suitable propellant, such as mercury. The lower end or botltom wall of the boiler is connected with a feeding device 2, constructedin accordance with the present invention, and the upper end or topI ofthe boiler is connected with a riser 3 for conducting mercury vapor toan aspirator nozzle from which the mercury vapor issues as a highvelocity jet into a mixing chamber 5.

` The mixing chamber 5 is connected by 'a vapor fduct 6 to a cooler iwhich normally contains a The 'drain pipe i2 connected to the lower endof the funnel, while the refrigerant vapor flows vpwardi" lythrough avapor duct iltto the refrigerant condenser l5. The condensed refrigerantis received from the condenser i5 by a return pipe l5 having a trap Ilat its lowerV end which contains a smaii body of mercury. Refrigerantliquid piling 'up in the pipe i6. develops suilicient head so that lsomeof the refrigerant may pass by the mercury into` the trap and ow througha pipe i8 back to the cooler T.

A trapY i9? has one leg connected 'to the bottom of the cooler 'l andits other leg is connected with a downwardly inclined pipe 2d. The trapcontains -a bod-'yof mercuryv and the construe* tion and arrangement ofparts are such that when 'stray mercury is received from the cooler, themercury may overflow the trap It intor the pipe 201. The lower end ofthe drain i2 also. communi- Cates through a trap 2i with the lower endof the inclined pipe 2i! which is connected toA a return line 22. The.pipe 22 is; connected to a check valvev 2d which in turn is connected toIa return pipe 2'5 communicating with the lower end of the feedingdevice 2. `The check velvet 2A, as shown in'FigsQ' and 4, comprises acylindrical member having a truste-conical, shaped interior abovev whichis a square or non-circular; shaped dist.Y 26 having aflat upper surfaceadapted to seat against the flat under-surface of the head or: closureplate 28, in response to back pressure or fluid ow, thereby to vpermitflow of uid only toward the feeding device 2, as indicated by the arrowsin Fig. 2. v

.fIThe feeding deviceor bumper feed 2A comprises an elongate verticallydisposfd cylindrical ube having, a closed lower end wall 3| to whch the.return pipe 25' is connected. Within the tube 311 is disposed aplurality of transversely extending partitions providing aligned checkvalves, caen consisting of an inverted dishfshapedcircular valve member32 having a 'central opening 33 in its top wall and a side wall which istapered or beveled as indicated at 34 adjacent to its junction with thetop wall so as to dene a chamber having a frusto-conical upper end, asshown in Figs. 2 and 3. A gravity-operated flat valve disk 35 of squareor non-circular shape seats squarely on the upper face of each valvemember 32 so as normally to close its associatedv valve opening 33.` Thevalve members 32 thus denne a series of spaced compartments, each havingcodirected valves operative to permit uid to pass upwardly in responseto a pressure surge or wave, but opposing downward movement of thefluid. It will be observed that due to the non-circular shape of thevalve disks 35 and the frusto-conical shape of the valve members 32,each valve disk is inelectve to close the valve opening just above itwhen forced from its seat. Hence, a surge or pressure wave createdwithin any compartment is effective to seat the valve disk; within thatcompartaient rmliy on its seat so as to prevent downward flow of and atthe same time raise or unseat the valve dishl of the compartment nextabove.

The upper end of' the feeding device 2` may be welded or otherwisesuitably secured to the boiler I, and both are disposed within the rebox- C so that the feeding device is positioned to receive adequate heatfrom the burner B to effect the bumping action, it being understood thatthe burner B may be automatically controlled to supply fuel inaccordance with the requirements of the system.

A summary of the operation of the systemv is as follows VAssuming thatthe boiler l, trap Zi and return 2-2 contain the proper level' ofmercury, as indi- I' plied to the boiler lV and feeding device 2 catedin Fig. 1, and that the cooler l contains the proper amount of liquidrefrigerant, heat apenerates mercury vapor which passes through the tube3 int-o the aspirator nozzle fr from which the mercury vapor issues as ahigh velocity jet into the mixingv chamber 5, thereby' drawingrefrigerant vapor through the duc-t S, which is entrainedwith the streamofmercuryvapor. lCondensation of the mercury vapor takes place withinthe funnel 8', and the mercury condensate passes into the drain i2',through trap 2i into the return line 22, while the compressedrefrigerating vapor passes through the condenser i5` The mercurycondensate flows through the check: valve 24,4 as above explained, intothe feeding device 2. Since the mercury within the vapor-generatingcompartments of the feeding device E is subjected to the main body ofthe flame issuing from the burner B, it is superheated suilciently toeect the desired bumping action, and hence feeds the return fluid in theform of mercury vapor and entrained liquid mercury back into the boileri. When all the returned mercury in return-line 22 has been fed, therate of pumping will of course diminish for lack of supply, and when themercury contained in the feeding-device has been reduced sunlciently,feeding will cease until more returnf mercury accumulates. The valves,however, com tinue to maintain the pressure-difference. Thus thefeeding-device is self-regulatory, functioning only as there is liquidto be fed.

pose of illustration and' that variousy changes and modifications may-be made without depart;

ing from the spirit and scope of the invention as set forth in theappended claims.

I claim:

1. A heat-operated Huid-feeding device which comprises the combinationof a heat generator and an enclosed chamber having an inlet and anoutlet, and a plurality of co-directed checkvalves defining a pluralityof vapor-generating zones between an inlet and an outlet in heattransfer relation to said generator, said checkvalves being effective topermit unidirectional fluid-flow from inlet to outlet and to preventcounter-flow.

2. A heat-operated fluid-feeding device which comprises the combinationof a heat generator and an elongate member having an outlet at one endand an inlet at its opposite end, and a plurality of co-directed checkvalves within said member interspaced between said inlet and outlet anddeiining a plurality of vapor-generating zones in heat transfer relationto said generator, said check valves being effective to permit fluid owonly in a direction toward said outlet.

3. A heat-operated fluid-feeding device which comprises the combinationof a heat generator and an elongate passage having an inlet at one endand an outlet at its other end, a plurality of spaced partitionsextending across said passage and defining a plurality ofvapor-generating compartments in heat transfer relation to saidgenerator, each partition having a valve opening and a valve seat aboutsaid opening, and a normally closed valve member associated with eachvalve opening and arranged so as to permit uid ow only in a directiontoward said outlet.

4. A heat-operated fluid-feeding device which comprises the combinationof a heat generator and an elongate vertically disposed channel havingan inlet at its lower end and an outlet at its upper end, a plurality ofvertically spaced partitions extending across the interior of saidchannel and defining a plurality of vapor-generating compartments inheat transfer relation to said generator, each partition having a valveopening and a valve seat extending about said opening, and a gravityoperated valve disk disposed on each seat for normally closing the valveopening, the valve disks being arranged so as 6 to permit fluid flowonly in a direction toward said outlet.

5. A heat-operated uid-feeding device which comprises the combination ofa heat generator and an elongate cylindrical tube having an inlet at oneend and an outlet at its opposite end, a plurality of axially spacedpartitions extending across said tube and defining a plurality ofvapor-generating compartments in heat transfer relation to saidgenerator, each partition having a valve opening and a valve seatextending about said opening, the wall of each partition facing theinlet end of said tube being of frustoconical shape, and a normallyclosed valve disk of non-circular shape disposed against said seat, thevalve disk being operative to permit fluid flow only in a directiontoward said outlet.

6. A heat-operated fluid-feeding device which comprises the combinationof a heat generator and an elongate vertically disposed cylindrical tubehaving an inlet at its lower end and an outlet at its upper end, aplurality of vertically spaced partitions extending across said tube anddefining a plurality of vapor-generating compartments in heat transferrelation to said generator, each partition having a centrally disposedvalve opening, the upper face of each partition defining a flat valveseat extending about said opening and the undersurface of each partitionbeing of frusto-conical shape, and a grav-y ity operated non-circularvalve disk disposed on each seat, the valve disks being collectivelyoperative to permit flow of fluid only in a direction toward saidoutlet.

EASTMAN A. WEAVER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,624,014 Schneider Apr. 12,V1927 2,174,301 Whitney Sept. 26, 1939 FOREIGN PATENTS Number CountryDate 850,942 France Sept. 25, 1937

